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Nitrogen Source Study on Potatoes

IPNI-2005-USA-MD12

Overview Related Article
01 Sep 2005

Methodology


Rotation:
White Potatoes, Wheat/Doublecropped Soybeans, Grain Corn and Single Crop Soybeans. Note: The experiment is set up so each crop will be evaluated each year.
Example of a Rotation Cycle: Notill and Zoned Tilled grain corn, Notill and Minimum Tilled Soybeans, Conventional Tilled(chisel plowing/discing) White Potatoes planted into the continuos notill and minimum tilled strips, Notill/Minimum Tilled Wheat/Double Cropped Soybeans.

Fertility Program: All major and minor soil nutrients will be maintained at a U of MD recommended maximum nutrient management level.
  1. Check, Grain crops no nitrogen. Potato crop to receive a modest amount of N(54 lbs/a), applied preplant.
  2. Grain crops urea, N(120 lbs/a) Applied preplant . Potatoes, N applied 3 times (preplant, 1st sidedress @ emergence, 2nd sidedress @ hilling).**
  3. Grain crops 120 lbs N/a. AMS (125 lbs/a) blended with Urea(204 lbs/a) applied preplant. White Potatoes, N applied 3 times (preplant, 1st sidedress @ emergence, 2nd sidedress @ hilling).** Potatoes AMS applied preplant and @ emergence. No AMS at hilling.
  4. Grain crops 120 lbs N/a. AMS level divided in half. Half rate(63 lbs/a AMS + 204 lbs/a urea) applied preplant and ½ rate AMS(63 lbs/a) approximately 3 weeks post plant. White potatoes, N applied 3 times (preplant, 1st sidedress @ emergence, 2nd sidedress @ hilling).** White Potatoes AMS in 3 applications, 1st preplant, 2nd preemergence and 3rd @ hilling.

**White Potato Fertilization
    Fertilizer Sources used in study: Nitrogen & Calcium (Ammonium Nitrate (34-0-0), Ammonium Sulfate (21-0-0-24) and Calcium Nitrate (15-0-0-19(Ca)), Phosphorous (0-46-0) & Potassium (0-0-60).

Four Treatments will be evaluated in study
    Treatment 1. Total Fertility 54-100-55-55(Ca)
      • Broadcast and tilled into soil by chisel plowing/discing (54-100-55-55(Ca),
      • Fertilizer Sources: Nitrogen & Calcium(Ammonium Nitrate 34-0-0, and
      • Calcium Nitrate 15-0-0-19(Ca)), Phosphorous 0-46-0 & Potassium 0-0-60
    Treatment 2. Total Fertility 179-100-120-55(Ca)
      • Broadcast and tilled into soil by chisel plowing/discing(54-100-55)
      • 1st sidedress, cultivated into soil while potatoes are covered up(69-0-65-36(Ca)
      • 2nd sidedress, cultivated into soil while potatoes are hilled(57-0-0-19(Ca)).
    Treatment 3. Total Fertility 179-100-120-78(S)-55(Ca)
      • Broadcast and tilled into soil by chisel plowing/discing(54-100-55-43(S)).
      • 1st sidedress, cultivated into soil while potatoes are covered up (74-0-65-35(S)-36(Ca)).
      • 2nd sidedress, cultivated into soil while potatoes are hilled(51-0-0-19(Ca)
    Treatment 4. Total Fertility 179-100-120-78(S)-55(Ca)
      • Broadcast and tilled into soil by chisel plowing/discing(54-100-55-43(S)).
      • 1st sidedress, cultivated into soil while potatoes are covered up (68-0-65-28(S)-36(Ca)).
      • 2nd sidedress, cultivated into soil while potatoes are hilled(57-0-0-7(S)-19(Ca)).